“As you’d expect, contact has been made with the Trump administration setting out our view that we believe the leak is unacceptable.” Foreign Secretary Jeremy Hunt said the culprit would face “very serious consequences if and when we find out who was responsible.”

The British parliament’s foreign affairs committee chairman Tom Tugendhat called the leak a “betrayal” that was “deeply damaging to the integrity of the UK.”

The Daily Telegraph newspaper said such memos are seen by up to 100 people working in the Foreign Office and other government departments.

“But it would require a single official or minister to have access to the whole cache, inevitably casting the spotlight on senior ministers,” it wrote.